Patent application title: METHOD FOR FOLDING IN OR FOLDING OUT AN ELECTRICALLY OPERATED TRAILER COUPLING, AND ELECTRICALLY OPERATED TRAILER COUPLING

Abstract:

In a method for folding in or folding out an electrically operated trailer
coupling for vehicles which can be moved electrically between a
folded-out use position and a folded-in rest position with excess force
limitation, an actuating device is provided for activating the trailer
coupling. A brief actuation of the actuating device results in an
automatic adjusting movement of the trailer coupling in the folding-in or
folding-out direction. In the method, in the event of a continuous
actuation of the actuating device, the excess force limitation threshold
is increased during the automatic adjusting process of the trailer
coupling, and after the actuating device is released, the automatic
adjusting process is continued with the original excess force limitation
threshold until the trailer coupling has reached its use or rest
position.

Claims:

1. A method for one of folding in and folding out an electrically operated
trailer coupling for vehicles which can be moved electrically between a
folded-out use position and a folded-in rest position with excess force
limitation, which comprises the steps of:actuating an actuating device
for activating the trailer coupling, and a brief actuation of the
actuating device resulting in an automatic adjusting movement of the
trailer coupling in one of a folding-in direction and a folding-out
direction;increasing an excess force limitation threshold during an
automatic adjusting process of the trailer coupling in an event of a
continuous actuation of the actuating device; andcontinuing the automatic
adjusting process with an original excess force limitation threshold
until the trailer coupling has reached one of a use position and a rest
position, after the actuating device is released.

2. The method according to claim 1, which further comprises, in an event
of a continuous actuation of the actuating device, raising the excess
force limitation threshold and, in an event of the actuating device
subsequently being released again, reducing the excess force limitation
threshold again to an original value.

3. An electrically operated trailer coupling for use in vehicles, the
coupling comprising:a coupling unit which can be one of folded in and
folded out electrically;an actuating device for activating said coupling
unit, a brief actuation of said actuating device resulting in an
automatic adjusting movement of the trailer coupling in one of a
folding-in direction and a folding-out direction; andcontrol means
programmed to:increase an excess force limitation threshold during an
automatic adjusting process of the trailer coupling in an event of a
continuous actuation of said actuating device; andcontinuing the
automatic adjusting process with an original excess force limitation
threshold until the trailer coupling has reached one of a use position
and a rest position, after said actuating device is released.

Description:

CROSS-REFERENCE TO RELATED APPLICATION

[0001]This application claims the priority, under 35 U.S.C. §119, of
German application DE 10 2009 012 709.7, filed Mar. 11, 2009; the prior
application is herewith incorporated by reference in its entirety.

BACKGROUND OF THE INVENTION

Field of the Invention

[0002]The invention relates to a method for folding in or folding out an
electrically operated trailer coupling for vehicles which can be moved
electrically between a folded-out use position and a folded-in rest
position with excess force limitation. An actuating device is provided
for activating the trailer coupling, and a brief actuation of the
actuating device results in an automatic adjusting movement of the
trailer coupling in the folding-in or folding-out direction.

[0003]The prior art discloses trailer couplings which can be fastened to a
vehicle and which can be pivoted by an activatable motor between a use
position and a rest position. The trailer coupling can be connected to
the vehicle, for example, by fastening plates in order to transmit acting
forces into the vehicle chassis. Here, the ball rod or the ball neck
pivots in and out for example at the touch of a button. The operation may
take place by an operating button in the interior of the vehicle, for
example in the luggage compartment, or optionally by remote operation.

[0004]It is generally conventional in the case of electrically pivotable
trailer couplings to implement a "manual mode" (button operation) and an
"automatic mode" (tapping operation). Excess force limitation is
conventionally active or provided both in the manual mode and automatic
mode. Here, the excess force limitation is higher in the manual mode than
in the automatic mode. In this way, it is possible for any hindrance in
the automatic mode, which would normally trigger a reversal, to be
overrun by the manual mode.

[0005]In the manual mode, the trailer coupling accordingly pivots only
when the operating button is actuated constantly (continuously). When the
operating button is released, the pivoting movement is stopped. The
disadvantage is therefore the fact that the trailer coupling pauses in
intermediate positions when the operating button is released, and the
operator must keep the operating button pressed continuously in order to
fully deploy or fully retract the trailer coupling.

SUMMARY OF THE INVENTION

[0006]It is accordingly an object of the invention to provide a method for
folding in or folding out an electrically operated trailer coupling, and
an electrically operated trailer coupling which overcome the
above-mentioned disadvantages of the prior art methods and devices of
this general type, which trailer coupling ensures a reliable adjustment
of the trailer coupling into its respective end positions.

[0007]With the foregoing and other objects in view there is provided, in
accordance with the invention a method for folding in or folding out an
electrically operated trailer coupling for vehicles which can be moved
electrically between a folded-out use position and a folded-in rest
position with excess force limitation. A actuating device is actuated for
activating the trailer coupling, and a brief actuation of the actuating
device results in an automatic adjusting movement of the trailer coupling
in one of a folding-in direction and a folding-out direction. An excess
force limitation threshold is increased during an automatic adjusting
process of the trailer coupling in an event of a continuous actuation of
the actuating device. The automatic adjusting process is continued with
an original excess force limitation threshold until the trailer coupling
has reached a use position or a rest position, after the actuating device
is released.

[0008]The main advantages which can be obtained with the invention are
that, by the method or by the corresponding trailer coupling, it can be
ensured that triggered adjusting processes in the folding-in or
folding-out direction are reliably ended, specifically without the
trailer coupling pausing in undesired intermediate positions.

[0009]This is obtained substantially by a method which is characterized in
that, in the event of a continuous actuation of the actuating device, the
excess force limitation threshold is increased during the automatic
adjusting process of the trailer coupling, wherein after the actuating
device is released, the automatic adjusting process is continued with the
original excess force limitation threshold until the trailer coupling has
reached its final use or rest position. This has the advantage that no
undesired pausing takes place in intermediate positions, since the
adjusting process is continued with the normal excess force limitation
threshold in the automatic mode after the actuating device is released.
It is therefore possible to dispense with a separate manual mode in which
the trailer coupling is moved into the respective end position only by a
continuous actuation of the actuating device.

[0010]It is for example provided that, in the event of a continuous
actuation of the actuating device, the excess force limitation threshold
is constantly raised and, in the event of the actuating device
subsequently being released again, the excess force limitation threshold
is reduced again to the original value which is set in the automatic
mode. For example, the excess force limitation threshold may always be
raised until it can be ensured that hindrances in the automatic mode can
be reliably overrun.

[0011]The invention also relates to an electrically operated trailer
coupling for use in vehicles, having a coupling unit which can be folded
in or folded out electrically, having an actuating device for activating
the coupling unit, and having a corresponding control device for carrying
out the method according to the invention.

[0012]Other features which are considered as characteristic for the
invention are set forth in the appended claims.

[0013]Although the invention is illustrated and described herein as
embodied in a method for folding in or folding out an electrically
operated trailer coupling, and an electrically operated trailer coupling,
it is nevertheless not intended to be limited to the details shown, since
various modifications and structural changes may be made therein without
departing from the spirit of the invention and within the scope and range
of equivalents of the claims.

[0014]The construction and method of operation of the invention, however,
together with additional objects and advantages thereof will be best
understood from the following description of specific embodiments when
read in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

[0015]FIG. 1 is a flow chart illustrating an adjusting process according
to the prior art; and

[0016]FIG. 2 is flow chart illustrating a method according to the
invention.

DETAILED DESCRIPTION OF THE INVENTION

[0017]Referring now to the figures of the drawing in detail and first,
particularly, to FIG. 1 thereof, there is shown a schematic functional
diagram illustrating an adjusting process of an electrically operated
trailer coupling according to the prior art.

[0018]The electrically operated trailer coupling can be operated in an
automatic mode 1 and with a manual mode 2.

[0019]If the operating button (actuating device) is actuated by being
tapped, the automatic mode starts and the trailer coupling is retracted
or deployed with a low excess force limitation threshold. If the trailer
coupling reaches its respective end position (rest or use position), the
electric drive for adjusting the electrically operated trailer coupling
is stopped.

[0020]If unanticipated hindrances arise during the adjusting process in
the automatic mode, the operating arrangement provides a manual mode 2 by
which any hindrances in the automatic mode can be overrun. For this
purpose, the operating button must be actuated continuously, as a result
of which the excess force limitation threshold is raised and the
respective hindrance can be overrun.

[0021]If the operating button is released, the manual mode of the trailer
coupling stops and the trailer coupling remains in the respective
intermediate position. The trailer coupling can be moved into its
respective desired end position by re-starting the automatic mode or
manual mode.

[0022]FIG. 2 shows a schematic functional diagram illustrating the method
according to the invention for adjusting an electrically operated trailer
coupling.

[0024]If the operating button (actuating device) is actuated by being
briefly tapped, the automatic mode starts and the trailer coupling is
retracted or deployed with a low excess force limitation threshold. If
the trailer coupling reaches its respective end position (rest or use
position), the electric drive for adjusting the electrically operated
trailer coupling is stopped.

[0025]If the trailer coupling is unanticipatedly hindered or halted during
the adjusting process in the automatic mode, the method provides that, if
the operating button (actuating device) is actuated continuously, the
excess force limitation threshold is increased in order to ensure that
the hindrance which has arisen in the automatic mode can be overrun.

[0026]In contrast to the prior art, the release of the operating button in
this case does not lead to the trailer coupling coming to a standstill in
an intermediate position, but rather leads to the adjusting process being
ended automatically in the automatic mode. Consequently, the excess force
limitation threshold is likewise automatically reduced to the original
value for the automatic mode.

[0027]It may for example be provided that, if the operating button is
actuated constantly, the excess force limitation threshold is increased
constantly.